Aircraft



- May 11, 1943. R, TAMPIER 2,319,169 I AIRCRAFT Filed July 1a, 1940 Patented -May 11, 1943 AIRCRAFT Ren 'Iampier, Cricklewood, London, England Application July 18, 1940, Serial No. 346,196

, In Great Britain April 25, 1940 2 Claims.

This invention relates to aircraft and in particular to the power transmission in aircraft.

The primary object of the invention is to provide a change-speed gear in the transmission by means of which the speed of revolution of the airscrew or airscrews-may be adapted to the flight of the aircraft at different speeds and altitudes.

A further object of the invention is to provide an arrangement in which the drive from two engines can be transmitted commonly or separately to two airscrews.

The invention is illustrated diagrammatically in plan view in the accompanying drawing wherein in the fuselage I of an aircraft are disposed two engines 2, 3; the engine shafts of which project inside the casing 4 of a gear box and terminate in bevel gears 5, 6. The gear 5 meshes with a second bevel gear 1 solid on a sleeve 3 rotatably mounted on the power shaft 9 revolubly mounted in bearings in the casing 4. The other end of the sleeve 8 is solid with one part of a dog clutch III, the complementary part of which is keyed on the power shaft 9 and has a pc- 4 ripheral groove engaged by a clutch lever ll 29 on the power shaft 9 for the purpose hereinafter described.

A change speed gear is provided between the shafts 9 and I3 J3 and comprises two gear wheels 39, 3| of different diameters fixed on the power shaft 9, and two gear wheels 32, 33 also of different diameters carried on a sleeve 34 splined or keyed to the shaft I3 the sleeve 34 being formed with a peripheral groove engaged by a change speed lever 35 operable from the cockpit through a rod and pivoted lever transmission 36. In operation, with the parts as shown the transmission shaft I3 l3" and airscrew shafts 29, 2| are driven at a speed higher than that of the engine shafts, both of which drive the transmission shaft through clutches I0, I0 power shaft 9, gears 39, 32 and clutch 24. If it is desired to reduce the speed of the two airscrews the transmission 39 is operated to slide the gears 32, 33 to the right, through a neutral position (in which both engines are disconnected from the transmission shaft), into a position in which the parts I3 I3 disposed parallel to the power shaft clutch-comprising a part 24 fixed to the end of the part I3 and a part 25 splined or keyed t0 the other part I3 The part 25 is made solid with a gear wheel 26 and is grooved to receive a clutch lever 21 operable from the cockpit by a rod and pivoted lever transmission 23. When the clutch 24, 25 is disengaged the gear wheel can be moved into engagement with a gear wheel gear 33 engages the gear 3|.

In the event of failure of one engine the corresponding clutch Ill or I0 is-disengaged and both airscrews are then driven by the single engine remaining in operation.

If it be desired to drive the airscrews separately, each by one engine, the clutches I0 and 24 are disengaged and the clutch part 25 and gear 26 moved to the right, the latter to engage the gear 29, The engine 2 then drives the propeller 23 through gears 6, I sleeve 8 gears 29,

.26 and the part Ill of the transmission shaft.

The engine 3 may continue to drive the part I3 of the transmission shaft through the clutch I9 as above described.

The invention has the following advantages.

By permitting of adapting the speed of revolution of the airscrew drive of an aircraft to different speeds of the aircraft and different altitudes an economy in fuel is obtained. Only a single gear box need be employed for more than one engine, and the arrangement described is such that both engines can turn at the same speed, this beingof particular advantage when taking off, when differences in engine speed may affect the stability of the machine. In the event of failure of one engine, a second engine can be used to drive both airscrews, whilst the possibility of separately driving each airscrew is retained, for example when taxi-ing on grounder water.

The shafts between the engines and the gear box and/or between the gear box and airscrews,

instead of being as shown may be of the kind described in my pending patent application Serial No. 342,328, or of any other kind.

The change speed gear may have more than two speed ratios if desired.

The details of construction may evidently be different from those shown in the'drawing. For example, worm gears or other kinds of gear wheels and clutches other than dog clutches may be used. The gear box can comprise more than one part, each part containing one part of the gears.

More than two engines may be used. For example, two further engines may be arranged in the same fuselage and may drive airscrews dis-' posed further from the fuselage than the two engines shown. More than one fuselage, each containing an engine or engines may be carried on the same wing.

What I claim is:

1. In an aircraft having a plurality of propellers, a plurality of power plants for driving the propellers, a driving shaft and operator controlled means to couple said driving shaft selectively to allor any selected one of said power plants, the combination of a transmission shaft comprising several parts each drivingly connected with one of said propellers, operator controlled means whereby all the parts of said transmission shaft can be drivingly connected with or disconnected from one another, a gear for coupling one part of said transmission shaft to said driving shaft, and means for drivingly connecting another part of said transmission shaft directly to one of said power plants.

operator controlled clutch between said alined parts, a change speed gear between said driving shaft and one of said alined parts, a gear wheel rotatable with the other alined part, and means to bring said last mentioned gear wheel into driving mesh with said gear wheel on said sleeve thereby causing one of said propellers to be driven directly from one of saidpower plants without the use of the driving shaft.

RENE TAMPIER. 

